Song types and their structural features are associated with specific contexts in the banded wren

Abstract

We studied the use of song types and their acoustic features in different social contexts in the banded wren (Thryothorus pleurostictus), a resident tropical songbird in which males possess about 20 distinctive song types varying in duration, bandwidth, note composition, and trill structure. We recorded six focal males intensively for four days each while we observed context information such as during versus after dawn chorus, presence of the female, counter-versus solo-singing, location at the edge versus centre of the territory, and proximity to the nest. All males used at least some song types differentially during each of these pairs of alternative contexts. Males also preferentially used the song types they shared with a given neighbour when interacting with that bird. Songs delivered during dawn chorus were significantly longer, wider in bandwidth, often compound (double songs), and more likely to contain a rattle or buzz and an up-sweeping trill, compared to songs delivered after dawn chorus. Similar features were also more commonly observed when birds were engaged in intense male-male interactions and boundary disputes after dawn chorus, especially when countersinging at the edge of the territory. The presence of the female caused the male to deliver song types with narrower whole-song and trill bandwidth and fewer rattles and buzzes, and songtype diversity and fraction of compound songs were higher when the female was present. Thus, in addition to using type matching and variations in song-type switching and diversity to signal different levels of aggressive intention, male banded wrens also select song types based on their acoustic structure in different social contexts.In approximately 75% of oscine songbird species, male singers possess repertoires of two or more distinct song types acquired by innovation or imitative learning (MacDougall-Shackleton 1997). Some studies have suggested that each song type conveys the same message and that the primary function of song types is to increase stimulus diversity, reduce habituation of the receiver, and/or relieve stress on syringeal muscles (Nottebohm 1972;Hartshorne 1973;Krebs et al. 1978;Searcy et al. 1982;Lambrechts & Dhondt 1988;Searcy 1992). However, studies on a growing number of species indicate that song types are used selectively in different contexts and therefore probably convey different messages (reviewed in Catchpole and Slater 1995).Context-specific use of song types was first described in the wood warblers (Parulinae), where males were found to possess two acoustically distinct categories of song types apparently specialized for use in intersexual versus intrasexual communication (reviewed in Spector 1992). Type I songs are sung during daylight, relatively slowly, and when near females or by unmated males, suggesting a mate attraction function. Type II songs are sung rapidly in a dawn bout and later in the day during encounters with rival males or while close to territory boundaries, suggesting a territorial function. These associati...

Trill consistency is an age-related assessment signal in banded wrens

“…Since stimulus pairs were obtained from the same individual, we can exclude the possibility that individual quality differences between source birds contributed to the perceived difference between the stimuli. In addition, we used the same song type for the two stimulus types (figure 1) and thus there were no semantic differences between the stimuli ( Trillo & Vehrencamp 2005). It appears therefore that the perceived difference is due to the phenotypic, age-related differences in the songs used as stimuli.…”

Female song and vocal interactions with males in a neotropical wren

“…We tested for sex differences in song length by comparing means for males and females within 12 pairs, based on all of their songs. Most female songs were classifiable into types similarly to male song types in this species (Molles, 1999;Trillo and Vehrencamp, 2005). We generated plots of cumulative repertoire size vs. number of songs recorded for each of the 12 females to assess whether we could estimate their repertoire sizes reasonably accurately: only five females with 50 or more songs recorded appeared to reach an asymptote.…”

Biologie de la reproduction de la Paruline à gorge grise (Oporornis agilis) dans les pinèdes grises du Lac-Saint-Jean, Canada /

“…Song is used for territory protection (Searcy et al 2000;Trillo et Vehrencamp 2005) and mate attraction (Nowicki et al 1998;Gil et Gahr 2002 Hennin et al 2009) unpaired males sing also more than paired males probably because they need to attract females. It's a compromise between singing activities and reproductive behavior.…”